Radio-controlled flying craft and method

ABSTRACT

A homeostatic flying hovercraft preferably utilizes at least two pairs of counter-rotating ducted fans to generate lift like a hovercraft and utilizes a homeostatic hover control system to create a flying craft that is easily controlled. The homeostatic hover control system provides true homeostasis of the craft with a true fly-by-wire flight control and control-by-wire system control.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/791,253, filed Jul. 3, 2015, entitled “Method for Operating aRadio-Controlled Flying Hovercraft” (which issues as U.S. Pat. No.9,904,292 on Feb. 27, 2018), which is a divisional of U.S. patentapplication Ser. No. 13/092,940, filed Apr. 23, 2011, entitled“Homeostatic Flying Hovercraft” (which issued as U.S. Pat. No. 9,073,532on Jul. 7, 2015), which is a continuation of U.S. patent applicationSer. No. 11/838,040, filed Aug. 13, 2007, entitled “Homeostatic FlyingHovercraft” (which issued as U.S. Pat. No. 7,931,239 on Apr. 26, 2011),which was a division of U.S. patent application Ser. No. 10/526,153,filed Jan. 26, 2006, entitled “Homeostatic Flying Hovercraft,” which wasa national stage entry of PCT Application No. PCT/US03/27415, filed Sep.2, 2003, entitled “Homeostatic Flying Hovercraft,” which claimedpriority to U.S. Provisional Application No. 60/407,444, filed Aug. 30,2002, entitled “Homeostatic Flying Hovercraft,” the disclosures of eachof which are hereby incorporated by reference.

This application is also related to U.S. patent application Ser. No.15/272,414, filed Sep. 21, 2016, entitled “Radio-controlled flyingcraft” (which issued as U.S. Pat. No. 9,645,580 on May 9, 2017), whichis a divisional of U.S. patent application Ser. No. 14/791,253, filedJul. 3, 2015, entitled “Method for Operating a Radio-Controlled FlyingHovercraft” (which issues as U.S. Pat. No. 9,904,292 on Feb. 27, 2018).

FIELD OF THE INVENTION

The present invention relates generally to the field of heavier-than-airaeronautical craft that arc sustained in air by the force of a fluidsuch as air. More particularly, the present invention relates to ahomeostatic flying hovercraft and to a radio controlled flying saucertoy employing the principals of a homeostatic flying hovercraft.

BACKGROUND OF THE INVENTION

Ever since the term “flying saucer” was first introduced in 1947, theconcept of a circular flying craft has become a staple of popularculture. Unlike conventional aircraft in which lift is produced by thedifference between the air flowing over the top versus the bottom of awing, most flying saucers have proposed using the aerodynamic effect ofa spinning disc to at least partially generate the lift required for thecraft. The flying disc toy known as the Frisbee® is perhaps the bestexample of this principle. While numerous concepts relating to spinning,flying disc-shaped craft have been put forth in a variety of patents andpublications, a practical embodiment of a self-powered flying saucer hasyet to be developed.

The concept of a heavier-than-air craft supported by a fluid instead ofwings or rotors predates even the Wright brothers' first flight. U.S.Pat. No. 730,097 issued in June 1903 described an airplane controlled bya jet propulsion arrangement that proposed using a pendulum valve tocontrol the operation of the jets as an automatic means to keep thecraft in equilibrium. Despite numerous attempts to realize the conceptof a craft suspended by downward directed jets, it was more than sixtyyears later before the Harrier jump jet actually achieved this goal withthe first practical vertical-take-off-and-landing (VTOL) aircraft. Evenso, the difficulty in controlling and maneuvering such a VTOL aircrafton both take-offs and landings, as well as transitions from vertical tohorizontal flight, continues to plague the general acceptance of VTOLaircraft as evidenced by the ongoing difficulties with the US MarineCorps' V-22 Osprey aircraft.

Various attempts have been made to use the inherent stability of aspinning disc or multiple spinning disc arrangement in order tostabilize a fluid suspended flying craft Examples of the use of jetpropulsion in connection with a spinning disc are shown in U.S. Pat.Nos. 3,199,809, 3,503,573, 3,946,970, 4,566,699, 5,351,911, 6,050,250,6,302,229, 6,371,406, 6,375,117, 6,572,053, and 6,575,401. Otherexamples of spinning annular rings or discs in a saucer-shaped craft arcshown in U.S. Pat. Nos. 2,863,261, 4,214,720, 4,273,302, 4,386,748,4,778,128, 5,072,892, 5,259,571, 6,053,451, 6,270,036, and 6,398,159.

Another approach to supporting a heavier-than-air craft has involved theuse of ducted fans, instead of jets or rotors, to provide the necessarythrust for supporting and propelling the craft. Patents directed to theuse of ducted fans to support a heavier-than-air craft date back to asearly as 1872 and include craft that relied solely on ducted fans (e.g.,U.S. Pat. Nos. 129,402, 905,547, 931,966, 996,627, and 1,816,707), aswell as craft that used ducted fans in combination with wings (e.g.,U.S. Pat. Nos. 1,291,345, 1,405,035, 1,959,270, 2,461,435, 2,968,453 and6,547,180) or craft using ducted fans in a helicopter-like craft (e.g.U.S. Pat. Nos. 1,911,041, 2,728,537, 3,199,809, 5,503,351, 6,402,488,and 6,450,446).

The first non-spinning disc shaped aerial craft with a single centralducted fan arrangement, as described in U.S. Pat. No. 2,567,392, usedshutters to control airflow and orientation of the craft. The problemwith this arrangement is similar to the problems encountered withhelicopters, namely the rotation of a single fan imparts a one-way spinor torque that must somehow be counteracted in order for the craft toremain stable. Most central ducted fan arrangements have since utilizedthe concept of two counter-rotating blades spinning on the same axis inopposite directions to overcome this single-fan torque problem. The mostfamous application of this concept was the 1950's Hiller flying platformas described in U.S. Pat. No. 2,953,321 that was based on work datingback to 1947 by Zimmerman. The Hiller flying platform was controlled byhaving the operator shift his weight to alter the center of gravity ofthe craft.

Other craft that use the co-axial counter-rotating blades for a centralducted fan arrangement have used vanes, louvers and duct arrangements tocontrol airflow from the ducted fans in order to control orientation ofthe craft (e.g., U.S. Pat. Nos. 2,728,537, 3,442,469, 3,677,503,4,795,111, 4,804,156, 5,178,344, 5,203,521, 5,295,643, 5,407,150,6,450,445, and 6,588,701). Patents also have described craft that use apivoting central ducted fan arrangement to control airflow andorientation (e.g., U.S. Pat. Nos. 2,730,311, 2,876,965, 2,968,318,5,421,538 and 6,224,452). Still other patents have described centralducted fan craft that used variable pitch angle blades to control theairflow and orientation of the craft (e.g., U.S. Pat. Nos. 2,968,318,3,002,709, and 3,395,876). The addition of tail fins and tail rotors ortail jet engines to a central ducted fan craft has been described inseveral patents (e.g., U.S. Pat. Nos. 2,988,301, 4,796,836, 5,035,377,5,150,857, 5,152,478, 5,277,380, 5,575,438, 5,873,545, 6,270,038,6,457,670, and 6,581,872). The addition of a gyroscope mounted to androtated by the propellers of the ducted fan to aid in stabilization ofthe craft has been described in U.S. Pat. Nos. 4,461,436 and 6,604,706.Combinations of one or more of the control techniques have also beenproposed in many of these patents as well as in U.S. Pat. No. 4,196,877.

Ever since the 1950's, there have been sporadic research projectssponsored primarily by various military organizations on the design ofenclosed rotorcraft vehicles. All of these designs to date have utilizeda single-axis rotor inside a cowl or protective ring arrangement thatforms a ducted fan. The most successful implementation of a single-axiscounter-rotating ducted fan arrangement has been the Cypher™ unmannedair vehicle (UAV) from United Technologies Corp. that operates as asingle-axis VTOL craft. The Cypher™ has been effectively used as a dronesurveillance probe by the military when remotely piloted by experiencedUAV pilots.

Recently, the military has started funding development of smallerunmanned air vehicles known as Organic Air Vehicles (OAVs) that areintended to be small (<24″ diameter) field-deployable remote controlledflying vehicles. Two multi-million dollar research and developmentcontracts were granted in 2001 for the OAV program. Both contractssought to extend the single-axis VTOL concept that is the basis for allmilitary enclosed rotorcraft into a number of smaller sizes. The VTOLcraft for the OAV program is designed to be oriented upright for takeoffand landings and transition into a sideways orientation for flight. Asone might expect, the trickiest part of controlling this craft occursduring the transitions between vertical and horizontal orientations.

In March 2002, the OAV design from Honeywell known as the Kestrel wasselected for further funding. The Kestrel design is a conventional VTOLsingle axis rotorcraft that looks like a 5 pound coffee can with bunnyears and legs and is powered by a gas engine in the center and a pair offuel carrying/payload bearing pods mounted on the sides. The Kestreldesign has three sizes from 9-29 inches, with payloads ranging from 8ounces to 18 pounds and an expected price tag of $10,000-$25,000 perunit. Available information indicates that these OAV's are beingdesigned for automated self-piloting based on GPS coordinates andcomplex object recognition vision systems. Currently availableinformation indicates that the smaller OAV models of the Kestrel projectare still not ready for use. For more information on the current statusof unmanned aircraft development, see “Future of Unmanned Aviation,”Popular Science, June, 2003.

One alternative to the VTOL central ducted fan arrangement is the use ofa pair of counter-rotating ducted fan arrangements that has beenproposed in both side-to-side and front-and-back positions in a craft(e.g., U.S. Pat. Nos. 2,077,471, 2,988,301, 3,752,417, 5,049,031,5,064,143, 5,213,284, 5,746,930, 5,890,441, and 6,464,166). A very earlyproposal for a ducted fan craft using more than a pair of ducts wasdescribed in 1911 by Gridley in U.S. Pat. No. 1,012,631. Grindley showedthe use of four ducted fans to produce a balanced (even) effect on theplane of the body of the craft, but no control arrangement for the fanswas described. U.S. Pat. No. 4,795,111 described an alternate embodimentof a UAV that employed four ducts and briefly proposed altering fanpitch control or throttle control as a means for controlling thisembodiment. U.S. Pat. Nos. 6,179,247 and 6,254,032 describe proposedflying passenger craft that use ten or more ducted fans arranged in anequidistant manner in a ring around the craft. Both patents brieflydescribe a control system that varies the throttle control of differentengines. U.S. Pat. No. 6,179,247 also proposes the use of a moveablepaddle system to deflect air for purpose of control, whereas U.S. Pat.No. 6,254,032 also proposes that each ducted fan is individuallypivotable to control airflow direction.

Until recently, most development efforts in heavier-than-air craft thatare fluid sustained using ducted fans of the like have been focused onlarger passenger aircraft of UAVs. Recent advances in battery technologyhave generated a renewed interest in the field of remote controlledaircraft and smaller OAVs. Instead of conventional gas-powered engines,a combination of high-powered batteries and light-weight electricalmotors have been used as replacement engines for model airplanes andmodel helicopters. While this represents an improvement in terms ofsimplicity and operability, model airplanes, and particularly modelhelicopters, are still expensive, complicated, temperamental and fragilehobby toys that can require months to build, learn, rebuild and master.

Various powered spinning disc toys and models have attempted to addressthe control and stability problems associated with model airplanes andmodel helicopters using many of the same approaches described above.These include single rotor model craft (e.g., U.S. Pat. Nos. 3,394,906,3,477,168, 3,528,284, 3,568,358, 3,608,033, 4,065,873 and 5,429,542),dual counter-rotating rotor model craft (e.g., U.S. Patent Nos.2,949,693, 5,071,383, 5,634,839, 5,672,086, and 6,053,451) and evenrocket or jet-powered models (e.g., U.S. Pat. No. 3,508,360 and4,955,962). U.S. Pat. No. 5,297,759 describes a disc-shaped model craftthat uses two conventional aircraft propellers mounted at an angle ofabout 30 degrees on the surface of the disc to rotate the disc toprovide both lift and propulsion.

More recently, variations on the conventional model helicopter have beenintroduced utilizing multiple main rotors, each powered by a separateelectrical motor. The Hoverfly® II is perhaps the best example of such acraft that utilizes three main rotors and a tail rotor in a classichelicopter format. The Ultimate Flying Saucer™, the GyroSaucer™ and theDraganFlyer III™ utilize four rotors (two pairs of counter-rotatingrotors) in a helicopter-like fashion to provide lift for the modelcraft, but do not have a separate tail rotor. Instead, the DraganFlyerIII™ uses three piezoelectric oscillation gyros to transmit flight datato an on-board computer to provide balanced reciprocal thrust among therotors. Another variation on this approach is the Vectron™ Blackhawkthat integrates a rotating outer ring with three rotor blades to providelift for the craft.

Unfortunately, each of these craft is still difficult to control andmaneuver and all of these craft rely on multiple conventional helicopterrotors to provide aerodynamic lift, rotors that are easily damaged inthe event of a crash. Like all exposed rotor craft, these multi-rotormodels are also inherently dangerous due to the exposed spinning rotors.

The most extensive research project using ducted fans instead of rotorblades was conducted by a research group at Stanford University for aNASA project to design miniature flying craft to be used for aerialmapping of Mars. The design known as a “mesocopter” calls for a verytiny battery-powered four rotor craft less than two inches across. Inone version, the four tiny rotors are each shrouded in a protectivering. While the research is interesting, the project has no practicalguidance on how to make a model-sized RC flying craft for here on Earthbecause of the differences in gravity and air density as compared toMars.

A design concept for a model flying hovercraft powered by ducted fanshas been proposed by a student at MIT. Although his design proposed theuse of counter-rotating ducted fans to power the craft, he has neverbeen able to make the design work. Control of his 4 ducted fan designwas to be achieved by using three separately controlled fins, one foryaw, one for left-right and one for back-forth. While some interestingconcepts were proposed, a workable prototype was never achieved and nofurther work on the project has been reported.

Whether the craft is a single-axis VTOL, ducted fan UAV or OAV, amulti-rotor model RC craft, or a multiple ducted fan craft, the mainchallenges with all of the existing designs for fluid sustained aircraftarc case of control and stability of flight. Manually flying any ofthese craft requires extensive training and skills. Unfortunately, theautomated self-piloting systems capable of attempting to assist withflying any of these craft are all based on the complicated and expensiveinertial guidance auto-pilot systems used in airplanes today.

Existing autopilot systems, such as the state-of-the-art HoneywellFault-Tolerant Air Data Inertial Reference System (FT/ADIRS), use one ormore gyroscopes to sense rotation about an axis in the form of angularvelocity detection. The FT/ADIRS, for example, is comprised of asix-sided structure holding six ring laser gyros and six accelerometers.A myriad of backup and redundant power supplies and computer systems areintegrated with this system to prevent a mid-flight failure.

The basic reason for the use of very high precision laser ring gyros andmultiple redundancies is that existing inertial guidance systems allrely on an initial static determination of the gravitational referenceto be used by the system. In the case of an autopilot system, thegravitational reference or ground horizon reference is established whenthe plane is on the ground. This process, commonly referred to asboresighting, establishes the gravitational reference for down. Oncethis gravitational reference is established, it is essentially staticand unchanging and the auto-pilot system uses the gyros to keep veryprecise track on a dead-reckoning basis of all changes in the attitudeof the craft from the point of the ground plane reference. Thiscomplicated referencing to a static ground plane reference can beaugmented dynamically by obtaining positional information from a globalpositioning satellite (GPS) system, but GPS systems are not preciseenough to detect small changes in attitude of a craft on a continualbasis.

Ideally, the ground plane reference could be dynamically updated on acontinual basis when the craft was in the air, thus eliminating the needfor the complicated gyro based inertial guidance systems. Unfortunately,mechanical sensors such as pendulums, gyros and piezo-accelerometers donot function the same in dynamic situations where the sensors arecontinually subjected to multiple acceleration fields. The impact ofprecession on those sensors means that the sensor readings will providean incorrect ground plane reference. By example, a pendulum is a verysimple and effective gravitational sensor in a static context. If apendulum is subjected to a centripetal acceleration in addition togravitational acceleration by swinging the pendulum in a circle, forexample, then the “reading” of the pendulum will not point down.Instead, the pendulum will point in a direction that is a combination ofboth the gravitational acceleration and the centripetal acceleration.This phenomenon is further complicated in situations where the craft isin a parabolic dive, for example, when the tilt of the craft is equal tothe rate of acceleration of the dive. In this situation, referred to asthe “death spiral,” the forces on sensor are balanced so that thesensors typically give no useful output readings in this situation.

U.S. Pat. No. 5,854,843 describes a virtual navigator inertial angularmeasurement system that uses gyros to sense angular velocity andpiezo-accelerometers to correct for drift in the gyros. While thepiezo-accelerometers are referred to in this patent as “absolute”references, it is understood that these piezo-accelerometers areabsolute only with respect to the initial gravitational ground planeestablished by a boresighting process. The need for this initialboresighting is confirmed by the fact that the invention touts theadvantage of being stable for long periods of time. If an inertialguidance system were able to dynamically update its initialgravitational ground plane, then the need for “stability” over extendedperiods of time is eliminated.

Examples of current state of the art inertial navigational referencesystems for aviation that use a gyro-based angular rate sensingarrangement similar to that described in U.S. Pat. No. 5,854,843 areshown in U.S. Pat. Nos. 5,440,817, 5,676,334, 5,988,562, 6,227,482,6,332,103, 6,421,622, 6,431,494, and 6,539,290. While certain referencesindicate that a gyro sensor can be a gravitational detector of down, itmust be understood that this statement is valid only under staticconditions or in a limited set of acceleration circumstances where theoutput of the sensor is not compromised by the acceleration fields. U.S.Pat. No. 6,273,370 attempts to overcome these limitations by trying tokeep track of different states of the sensor system and determining acourse of action based on the different state conditions. Still, if thesensor system loses track of the state of the sensor system, even thisarrangement cannot dynamically determine an inertial gravitationalreference to use as a reference.

What is needed is a heavier-than-air flying craft that has the abilityto hover and to perform vertical air movements like a conventional modelhelicopter, yet is easier to operate and more durable than existingflying machines.

SUMMARY OF THE INVENTION

The present invention is a homeostatic flying hovercraft that preferablyutilizes at least two pairs of counter-rotating ducted fans to generatelift like a hovercraft and utilizes a homeostatic hover control systemto create a flying craft that is easily controlled. The homeostatichover control system provides true homeostasis of the craft with a truefly-by-wire flight control and control-by-wire system control.

In one embodiment, the flying hovercraft is a flying saucer shapedover-powered skirtless hovercraft capable of up/down, lateral and yaw,pitch and roll flight maneuvers by mimicking the position of the craftto the position of a remote controller. Preferably, control is fluidlyintuitive by seamlessly utilizing a series of pre-establishedoperational orientations associated with each of the positions of thecraft that result in balanced and controlled flight positions. Thehomeostatic hover control system removes the need for the pilot to beconcerned with moment-to-moment balance/stabilization and control of thecraft and focus instead only on the intended motion in which the craftis to be directed.

Instead of trying to use the rotation of the craft or the spinning ofrotor blades to provide aerodynamic lift, the preferred embodiment ofthe homeostatic flying saucer uses four battery-powered ducted fanshoused completely inside the craft to produce four controlled cones ofthrust beneath the craft. A novel control system balances the four conesof thrust to keep the craft stable and to cause the craft to move in adesired direction. The fan blades are specially designed to make themost efficient use of the increased power provided by permanent magnetmotors while also reducing fan noise both because the blades spinsomewhat slower than conventional blades and because of the uniqueaerodynamic design features of the ducted fan blades.

The homeostatic control system of the preferred embodiment incorporatesmany different features to enable the craft to achieve homeostasis orself-stabilization. The ducted fans are angled slightly outward suchthat the four cones of thrust have an inherent balancing effect, muchlike the bottom of a Weeble® toy that wobbles but doesn't fall over. Thefour ducted fans are actually two pairs of counter-rotating fans onopposite sides of the craft. The counter-rotation eliminates the needfor anything like a tail rotor to prevent spinning of the craft causedby the spinning of the fans. A hover control system manages the amountof thrust produced by each ducted fan via four speed controllers. Thehover control system uses an XYZ sensor arrangement and associatedcontrol circuitry that dynamically determines an inertial gravitationalreference for use in automatically and continuously determining thespeed needed for each fan in order to keep the craft at a desiredorientation. Other embodiments of the hover control system supportcollision avoidance sensors and the ability to automatically change theway the flying hovercraft operates depending upon whether the craft isindoors or outdoors.

In a preferred embodiment, light-weight, high-torque permanent magnetmotors power the ducted fans. The preferred embodiment of such permanentmagnet motors are described in U.S. Pat. Nos. 6,236,561 and 6,342,746,the disclosures of which are hereby incorporated by reference. Unlikeconventional electric motors that use electromagnetic force created by aseries of wound coils within the motor to rotate a shaft, thesepermanent magnet motors control the flow of magnetic flux from powerfulpermanent magnets to rotate the shaft of the motor. Consequently, whenthese permanent magnet motors are used to turn a heavy load the motordoes not draw additional current from the battery. These one-of-a-kindelectric motors provide a combined total in excess of ½ horsepower tothe shafts of the four ducted fans, enabling an anticipatedthrust-to-weight ratio of greater than 2:1 and preferably greater than3:1 for an unloaded saucer. As a result, the saucer of the preferredembodiment is able to fly longer and farther than if it were powered byconventional motors that draw increasing amounts of current from thebattery in response to increasing loads on the motor.

The unique and intuitive one-handed bee controller also includes an XYsensor arrangement and associated control circuitry that allows thecraft to mimic the position of the controller in terms of yaw, pitch,roll and lateral flight maneuvers. In one embodiment, control of thecraft is fluidly intuitive by seamlessly utilizing a series ofpre-established operational orientations associated with each of a setof positions for the craft that result in balanced and controlled flightorientations. Together, the homeostatic control system and the beecontroller eliminate the need for the pilot to be concerned withmoment-to-moment balance/stabilization. In one embodiment, the beecontroller also features a USB connection port to permit downloading ofsoftware updates from the web via an Internet connection.

Unlike existing RC models that use inexpensive low frequency one-waycommunications, the preferred embodiment of the present inventionincorporates state of the art radio frequency communications. A unique900 MHz communication chip provides a two-way, multi-channelcommunication link between the controller and the saucer. This highspeed multi-channel communication link allows multiple saucers to fly inthe same area and communicate with each other to make advanced gamingand coordinated control possible. It also permits extensive datacommunications both to and from the saucer. Video images and other highbandwidth sensor inputs can be communicated from the saucer to thecontroller over this link.

In the preferred embodiment, multiple onboard microprocessors receivecommands from another microprocessor in the bee controller and, inresponse, instruct the homeostatic control system on a desiredorientation, angle and thrust for the craft. Preferably, radiocommunications between the microprocessor and the bee controller areused to keep the craft within a programmed maximum distance from thecontroller and the microprocessor automatically slows and reverses thecraft when it approaches the maximum range from the controller. For oneembodiment of an RC craft, the maximum distance is 500 feet from the beecontroller and the maximum speed is about 25 mph.

In a preferred embodiment, instead of heavier, conventional NiCadrechargeable batteries, state-of-the-art Lithium Polymer rechargeablebatteries are used as the electrical power source for powering thepermanent magnet motors. Lithium Polymer batteries provide the long-lifeand high power capacity required for this technology in the lightest andsmallest package.

In a preferred embodiment, the flying hovercraft is an RC flying saucerthat is constructed of a single EPP foam shell weighing between 30-42ounces unloaded. Although light-weight, the saucer is designed towithstand free falls of up to 5 feet without damage. Even though it isas lightweight as styrofoam, the advanced EPP foam that forms the shellis actually able to bend and still return to its original shape withoutbreaking.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional side view of the craft in accordance withone embodiment of the present invention.

FIG. 2 is a detailed cross-sectional view of the fan rotation of theembodiment of FIG. 1.

FIG. 3 is a schematic diagram of the remote controller and the craft ofthe embodiment of FIG. 1.

FIG. 4a is a schematic diagram of a general configuration of 4 liftmotor/ducted fans and an XY axis mercury tilt switch stabilizertransducer of the embodiment of FIG. 1.

FIG. 4b is a schematic diagram of XYZ axis piezoelectric gyros of theembodiment of FIG. 1.

FIG. 5 is a schematic diagram of a general configuration of 4 motors,speed controllers and motor enable counter of the embodiment of FIG. 1.

FIG. 6 is a timing diagram of a general duty cycle for operating thespeed controllers and motor enable counter of FIG. 5.

FIG. 7 is a top view of a general configuration of the XY axis tiltswitch stabilized transducer of the embodiment of FIG. 1.

FIG. 8 is a block diagram of the systems of the embodiment of FIG. 1.

FIG. 9 is a block diagram of the avionics of the embodiment of FIG. 1.

FIG. 10 is a schematic diagram of a general configuration of an XY axistilt switch stabilized transducer circuit of the embodiment of FIG. 1.

FIG. 11 is a schematic diagram of the homeostatic stabilizer circuit ofthe embodiment of FIG. 1.

FIG. 12 is a schematic diagram of the piezoelectric gyro output for theembodiment of FIG. 1.

FIG. 13 is schematic diagram of the control system for the motorcontrollers incorporating the outputs of the stabilizer circuits and thegyro circuit of the embodiment of FIG. 1.

FIGS. 14 and 15 are top views of alternate embodiments of the ducted fanblades.

FIG. 16 is an isometric view of a preferred embodiment of a homeostaticflying hovercraft in accordance with the present invention.

FIG. 17 is a side profile view of the embodiment of FIG. 16.

FIG. 18 is a top wireframe view of the embodiment of FIG. 16.

FIG. 19 is a side wireframe view of the embodiment of FIG. 16.

FIG. 20 is a bottom plan view of the embodiment of FIG. 16.

FIG. 21 is a side cutaway view of the embodiment of FIG. 16.

FIG. 22a is an isometric view of a hand-held bee controller for theembodiment of FIG. 16.

FIG. 22b is a side view of the hand-held bee controller of FIG. 22 a.

FIG. 23 is a cutaway view of one of the ducted fan assemblies of theembodiment of FIG. 16.

FIG. 24 is an isometric view of a fan blade for the ducted fan assemblyof FIG. 23.

FIG. 25 is a top plan view of the fan blade of FIG. 24.

FIG. 26 is a side view of the fan blade of FIG. 24.

FIGS. 27a, 27b, 27c and 27d are detail segment views of the fan blade ofFIG. 24.

FIG. 28 is an overall block diagram of a preferred embodiment of thehomeostatic control system.

FIG. 29 is a detailed block diagram of one embodiment of the homeostaticcontrol system of FIG. 28.

FIGS. 30a-30g are detailed schematic circuit diagrams of the embodimentof the homeostatic control system of FIG. 29.

FIG. 31 is a detailed block diagram of an alternate embodiment of thehomeostatic control system of FIG. 28.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated in FIGS. 16-20, a preferred embodiment of a homeostaticflying hovercraft 200 is presented in accordance with the presentinvention. The homeostatic flying hovercraft 200 has generally anellipsoid shaped body 200, having an upper surface 202 and bottomsurface 204. As illustrated in FIG. 18, the upper surface 202 iscomprised of a solid outer ring 206 of the saucer body 200 that extendsradially inwards from the periphery and a removable cover 208 containinga plurality of ventilation openings 210. Preferably, the cover 208 has aslightly greater curvature as compared to the outer ring 206. The lowersurface 204, as illustrated in FIGS. 17 and 20 is a solid structure withfour equally spaced circular duct openings 212. As illustrated in FIG.19, each duct opening 212 preferably is angled at ten to fifteen degreesfrom the vertical and contains a battery-powered ducted fan 214 mountedinboard from the duct opening 212.

FIG. 21 provides a side cutaway view of the homeostatic flyinghovercraft 200 highlighting the placement of one of the battery-poweredducted fan 214. The cover 208 is structurally supported about its outerradius and by a central support pillar 216. The remainder of thestructure, comprised of the area between the lower surface 204 and underthe outer ring 206 of the upper surface 202 is comprised of alightweight material such as a single EPP foam shell. Preferably, an airchamber 216 defined between cover 208 and upper surface 202 is upstreamfrom fan 214 and has a frustoconical shape to expand the volume ofavailable air.

Each fan 214 is powered from an internal pair of batteries 216. Insteadof heavier, conventional NiCad rechargeable batteries, state-of-the-artLithium Polymer rechargeable batteries are used as the electrical powersource for powering the permanent magnet motors. Lithium Polymerbatteries provide the long-life and high power capacity required forthis technology in the lightest and smallest package. Motor wire channel218 operably connects the battery 216 to the fan 214.

FIGS. 22a and 22b illustrate the hand-held bee controller 220 of thehomeostatic flying hovercraft 200. The hand-held bee controller 220preferably includes a control stick 222 mounted on the upper controlsurface 224 for thumb control. Directly below the control stick 222 onthe upper control surface 224 are a plurality of directional LEDs 226and a LED power indicator 228. The directional LEDS 226 are disposed torepresent the four directions. The hand-held bee controller 220 isdesigned to be held in the palm of one hand so that the fingers contactthe four-way video control pad 230 and power button 232 while the thumbengages the control stick 222. Preferably, a USB port 234 is disposed onthe aft face 236 along with antenna 238. The USB connection port 234permits downloading of software updates from the web via an Internetconnection.

Unlike existing RC models that use inexpensive low frequency one-waycommunications, the preferred embodiment of the present inventionincorporates state of the art radio frequency communications. A unique900 MHz communication chip provides a two-way, multi-channelcommunication link between the controller 220 and the saucer 200. Thishigh-speed multi-channel communication link allows multiple saucers tofly in the same area and communicate with each other to make advancedgaming and coordinated control possible. It also permits extensive datacommunications both to and from the saucer 200. Video images and otherhigh bandwidth sensor inputs can be communicated from the saucer 200 tothe controller 220 over this link.

It will be recognized that use of the hand-held bee controller is notlimited to a flying saucer but can be used to remotely control any radiocontrolled (RC) aircraft in a true control-by-wire, fly-by-wireconstruct. The hand-held RC controller includes a body adapted to beheld in one hand. A homeostatic control system IS positioned within thebody to sense a desired orientation of the RC controller by a userselectively positioning an orientation of the RC controller. Thehomeostatic control system includes an XYZ sensor arrangement andassociated control circuitry as previously described that dynamicallydetermines an inertial gravitational reference for use in sensing thedesired orientation. The RC controller also includes a bidirectionalradio frequency (RF) transceiver providing two-way RF communicationsbetween the RC aircraft and the hand-held RC controller thatcommunicates the desired orientation to the RC aircraft.

The RC aircraft includes at least one motor that provides motive forceto the RC aircraft and a power source operably connected to the at leastone motor and carried within the RC aircraft. The motor and power sourcecan be electric or gas powered. A homeostatic control system is operablyconnected to the at least one motor to automatically control the motorin order to maintain the desired orientation of the RC aircraft. Thehomeostatic control system also includes an XYZ sensor arrangement andassociated control circuitry as described above that dynamicallydetermines an inertial gravitational reference for use in automaticcontrol of the at least one motor. Finally, the RC aircraft has abidirectional radio frequency (RF) transceiver providing two-way RFcommunications between the RC aircraft and the hand-held RC controller.

The ducted fan assembly 214 is illustrated in FIGS. 23-27 d. FIG. 23 isa cutaway view of one of the ducted fan assemblies 214 of thehomeostatic flying hovercraft 200. Each ducted fan assemblies 214includes a motor mount 240 that is dimensioned to receive the motor 242.Each motor 242 is further comprised of an exterior rotating rotor 244and an interior fixed stator 246 that is operably mountable in motormount 240. A fan blade 248 is operably mounted on the exterior rotatingrotor 244. The fan blades 248 are specially designed to make the mostefficient use of the increased power provided by permanent magnet motors242 while also reducing fan noise both because the blades 248 spinsomewhat slower than conventional blades and because of the uniqueaerodynamic design features of the ducted fan blades.

There are at least six fan blades 248 extending from a central mountinghub 250 that is generally concentrically aligned with the motor mount240 through an exterior ring 252. FIGS. 27a, 27b, 27c and 27d arc detailsegment views of the fan blades 248. The fan blades 248 arc angled at aconstant attack angle across a chord of each blade 248. In a firstembodiment, the attack angle is greater than 20 degrees and less than 40degrees.

Referring now to FIGS. 28-31, a preferred embodiment of the homeostaticcontrol system 300 will be described. The homeostatic control system isoperably connected to the thrusters to automatically control a thrustproduced by each thruster in order to maintain a desired orientation ofthe saucer. The homeostatic control system includes an XYZ sensorarrangement 302 and associated control circuitry 304 that dynamicallydetermines an inertial gravitational reference for use in automaticcontrol of the thrust produced by each thruster. The control circuitry304 is preferably implemented in software operating on signals from theXYZ sensor arrangement that have been converted into digitalrepresentation by an A/D input port of a microcontroller/microprocessoron which the software is executing. Alternatively, the control circuitry304 may be implemented as hardware logic, software and processor logic,field programmable gate array (FPGA), application specific integratedcircuit (ASIC), firmware or any combination thereof.

In this embodiment, the XYZ sensor arrangement comprises an X-axissensor system, a Y-sensor system and a Z-axis sensor system. The X-axissensor system is positioned in an X plane of the body and includes atleast three first sensors that sense acceleration and gravity in the Xplane and at least three second sensors that sense acceleration only inthe X plane. The Y-axis sensor system is positioned in a Y plane of thebody and includes at least three first sensors that sense accelerationand gravity in the Y plane and at least three second sensors that senseacceleration only in the Y plane. The Z-axis sensor system is positionedin a Z plane of the body and includes at least one sensor that sensesyaw in the Z plane.

Preferably, the X-axis sensor system comprises two sets of activeaccelerometers and two sets of passive accelerometers oriented in the Xplane. Similarly, the Y-axis sensor system comprises two sets of activeaccelerometers and two sets of passive accelerometers oriented in the Yplane. In this embodiment, each set of active accelerometers comprises apair of active accelerometers oriented at 90 degrees with respect toeach other in the respective plane and each set of passiveaccelerometers comprises a pair of passive accelerometers oriented at 90degrees with respect to each other in the respective plane. Each of thepairs of active accelerometers and each of the pairs of passiveaccelerometers are positioned at 45 degrees offset relative to ahorizontal plane through a center of the body. Although the preferredembodiment will be described with respect to four sensors per plane, itwill be understood that increasing numbers of sensors per plane could beused to enhance the resolution and accuracy of the homeostatic controlsystem.

In this embodiment, the control circuitry includes conditioningcircuitry that independently conditions output signals from eachaccelerometer. The control circuitry also includes differentialcircuitry that independently operably subtracts output signals from theconditioning circuitry for the passive accelerometers from acorresponding output signal from the conditioning circuitry for theactive accelerometers to generate a raw tilt value for each of fourcorresponding pairs of active and passive accelerometers in each of theX plane and the Y plane. The control circuitry further includescomparison circuitry that compares a ratio of two of the fourcorresponding pairs of active accelerometers and passive accelerometerswith the other two of the four corresponding pairs of activeaccelerometers and passive accelerometers to determine a ratio of pairsof raw tilt values. An effective angle of an absolute position of theX-axis sensor system in the X plane is determined and an effective angleof an absolute position of the Y-axis sensor system in the Y plane isdetermined from the ratio of raw tilt values.

The control circuitry also includes accumulator circuitry thataccumulates the effective angles over time from which an angular rate ofchange is determined for each of the X plane and the Y plane. A seconddifferential circuitry operably subtracts the ratios of pairs of rawtilt values of each of the X plane and the Y plane from each of thecorresponding output signals of the active accelerometers to generate araw acceleration cross product vector for each of the activeaccelerometers. The control circuitry then uses processing circuitrythat normalizes each of the raw acceleration cross product vectors foreach of the active accelerometers in the X plane and the Y plane usingthe corresponding one of the effective angles for the X plane and the Yplane to generate a normalized cross product vector for each of theactive accelerometers. Second comparison circuitry compares a ratio ofthe normalized cross product vectors of two of the four correspondingpairs of active accelerometers with the normalized cross product vectorsof the other two of the four corresponding pairs of activeaccelerometers to determine a ratio of normalized cross product vectors.An effective magnitude of a true horizontal acceleration and a truevertical acceleration of the X-axis sensor system in the X plane isdetermined from this ratio of normalized cross product vector.Similarly, an effective magnitude of a true horizontal acceleration anda true vertical acceleration of the Y-axis sensor system in the Y planeis determined from this ratio of normalized cross product vector.

The detailed circuit schematic set forth in FIGS. 30a-30g detail to aperson skilled in the art the implementation of one embodiment of thehomeostatic control system.

Referring now to FIGS. 1-3, an overall view of another embodiment of thepresent invention of a radio controlled flying hovercraft 10 and theremote controller 12 is shown. Preferably, the hovercraft 10 is of amodular design, with all of the avionics 14, propulsion 16 and powercomponents 18 being easily replaceable. The remote controller 12 ispreferably provided with a thumb-activated throttle and yaw control 20and one or more finger operated trigger controls 22 and 24. It isfurther envisioned that remote controller 12 may incorporate forcefeedback and/or visual gauges.

As illustrated in FIG. 1, the hovercraft 10 is an ellipsoid comprised ofan upper surface 26 and lower surface 28. Both upper surface 26 andlower surface 28 are made of Nerf®-like foam material in a preferredembodiment. Alternatively, the body/shell may be made of Styrofoam,arcel, carbon fiber, Kevlar®, plastic or the like.

A central housing 30 is disposed within hovercraft 10. The centralhousing 30 contains the avionics module 14 and propulsion module 16modules. In the preferred embodiment, the central housing 30 includesbattery pack 32 in the form of rechargeable nickel metal hydride cells.Alternatively, power and even control signals can be provided to thecraft via a tether cable (not shown).

In one embodiment, the hovercraft 10 is provided with a laser emitterand detector 34 for playing laser tag. LEDs 36 are disposed about thecircumference to indicate that the craft has been hit. In alternateembodiments, speakers may also be used. Numerous variations in the taggame can be effected, such as having the craft 10 reduce power and/orstability in response to a hit, exercise a wobble routine in response toa hit, be deactivated after a certain number of hits and automaticallyland, respond in relation to the relative accuracy of the hit, or evenallow for recharging at a base station.

As illustrated in FIG. 2, the propulsion module 16 is disposed withinthe central housing 30. The propulsion module 16 is comprised of fourmotors 38 operably connected to four matching fans 40 each within aseparate duct 42. The ducted fans 40 are preferably tilted between 10-15degrees relative to the lower surface 28 of the hovercraft 10 to providea counter-balanced stabilization effect. A circular airflow is alsopreferably established between the ducts 42 and the motor housing 44 byway of ventilation passages 46. The ventilation passages 46 arc aplurality of openings located along the common wall 48 adjacent to duct42 and motor housing 44. The ventilation passages are located upstreamand downstream of the fans 40 so as to induce circulation through themotor housing 44 and around the motors 38 for cooling. However, themajority of the airflow generated by fans 40 is driven through thedownstream opening 50 of each duct 42.

FIG. 3 shows a preferred embodiment of a remote controller 12 thatprovides one-handed control operation with pitch and roll controlaccomplished by mimicking the pitch and roll of the craft 10 through theuse of XY axis transducers in the remote controller 12. For example, therotation of the operator's hand will result in a comparable rotation ofthe hovercraft 10. It is envisioned that the remote controller 12contains batteries, an antenna, and an optional vibration system tosignify laser strikes and/or out-of-range operation of the hovercraft10.

In this embodiment, a 2 digital channel bi-directional controller 12 ispreferably used with a transceiver in both the controller and the craft.Preferably, the transceiver operates in the 900-Mhz band, althoughoperation at the 72 Mhz or 400 Mhz bands is also possible. One channelis for digital transmit, the other channel is for digital receive.Preferably, transmissions are done in word packets using 9 bit bytes (8bits data, 1 bit parity). In one embodiment, a four byte preamble(alternating bytes of 0's and 1's) and four byte post-amble (alternatingbytes of 0's and 1's) precede and follow a predetermined length datapacket portion of the word packet. The use of a 2 digital channelbi-directional radio frequency (RF) communication scheme permitsmulti-users to be designated on the same RC channels by using unique IDcodes within a header of the data packet portion for a given combinationof controller and craft.

As illustrated in FIG. 4a , the four lift motors 38 and ducted fans 40are configured symmetrically about the XY axis. Disposed centrally tothe four lift motors 38 and ducted fans 40 are the XY axis mercury tiltswitch stabilizer transducers 52 of this embodiment. FIG. 4b illustratesthe arrangement of the positioning system 54 comprised of XYZ axis piezogyros 56 also contained within central housing 30. Each of the threegyros 56 provides angular rate information on the respective x, y and zplane.

As illustrated in FIG. 5, the four motors 38 are individually connectedto a motor speed control 58. Each motor speed control 58 is operablyconnected to a common motor enable counter 60. In a preferredembodiment, the hovercraft 10 is preferably overpowered for normalflight by a lift-to-weight ratio of at least 2:1 and preferably 4:1.This allows the hovercraft 10 to avoid overheating of the four motors 38and to maximize power and thrust. As illustrated in FIG. 6, theswitching frequency of the duty cycle is optimized for moment of inertiaof the ducted fans 40. Each motor 38 has a duty cycle staggered relativeto the other three motors 38.

In an alternate embodiment that provides for more efficiency, each ofthe ducted fans 40 has two counter-rotating multi-bladed units. A shaftdrive 62 connects the fans to four electric motors 38 mounted within acentral housing 30 in the middle of the hovercraft 10. Preferably, thecentral housing 30 is provided with EMF shielding around the motors 38.Since the motor units 38 are overpowered per lift-to-weight ratios, themotors 38 are rotated to maximize cooling and maximize power drain onthe battery 32.

As shown in FIG. 7, the XY axis tilt switch stabilizer 52 is a fluidsuspended tilt switch mechanism. The NSEW transducers 64 represent zerodegrees in the XY axis horizontal plane. The transducers 64 are at a(1-3 degree) offset from the set angle. The pairing of the transducersin one plane increases response time and reduces bounce effect of thetilt switch mechanism 52. Preferably, a simple debouncing circuitaccompanies each switch. N′S′E′W′ transducers 66 are set to (5-10degrees) offset from the zero point to establish predeterminedorientations for fly-by-wire XY axis pitch/roll control. It will berecognized that multiple degree sensors could be used to establish aplurality of different fly-by-wire preset orientations. It will also beunderstood that a variety of different tilt switch or gravity sensorscould be used to accomplish a similar effect.

FIG. 8 illustrates a block diagram detailing operation onboard thehovercraft 10 of one embodiment of the present invention. A signalinterpreter chip 70, powered by power unit 18 receives inputs from theradio control (R/C) receiver 68 as to directional commands. The R/Creceiver 68 is a digital unit capable of receiving the followingcommands—up, down, yaw left, yaw right, pitch up, pitch down, roll left,roll right, fire laser, engage shields, and other directional and/oroperational commands. To implement the commands, signal interpreter chip70 communicates with XY axis mercury tilt switch transducer 52, XYZpiezo gyros 56 and any other I/O devices 72. Once stability and headingare determined by the signal interpreter chip 70, the motors 38 areengaged by way of speed controllers 58. Feedback on position issubmitted to the remote control unit 12 through R/C transmitter 74.

FIG. 9 is a block diagram illustrating the avionics command system.Radio frequency (R/F) digital carrier signal 76 is decomposed by wordisolator 78 into words and then into smaller information packages bybyte isolators 80. The byte packages arc then segregated as up/down 82,pitch 84, roll, 86 and yaw 88. The command is converted by therespective voltage processor 90 and resistor circuit 92, for creation ofan appropriate up/down, pitch, roll or yaw velocity vectors.

FIG. 10 shows a general configuration of the XY axis mercury tilt switchstabilizer transducer circuit 52 in this embodiment. Roll right (RR) 94and roll left (RL) 96 are measured by circuit 52. A counter roll 98 iscalculated and converted to the appropriate voltage command 100 and 102.A similar circuit is used for N′S′E′W′ fly-by-wire roll/pitch settings.

FIG. 11 depicts a first embodiment of the stabilizer circuit for thehovercraft 10. The XY axis mercury tilt switch stabilizer transducers 52are linked electrically to the appropriate circuit for roll and pitchcorrection. For example, the N and S transducers 64 provide statusinformation with regard to pitch actuation 104 while the E and Wtransducers 64 provide status information with regard to roll actuation106.

FIG. 12 shows a block diagram for enable from the X stabilizer circuitor the Y stabilizer circuit to the piezo gyros 56. FIG. 13 shows aschematic diagram of the control system for the motor controllers 58incorporating the outputs of the stabilizer circuits 52 and the gyrocircuits 56. For example, voltage adder 108 computes inputs fromX_(gyro A), X_(stab A), Z_(gyro A), and V_(u/d). Voltage to frequencyconverters 110 made up of a 555 timer/op amp circuits convert thecombined voltage to a frequency for the respective motor speedcontrollers 58. FIGS. 14-15 show alternate embodiments of the ducted fanblades 40.

In operation, a fly-by-wire signal is sent to the hovercraft 10. NSEWtransducers 64 are sensed and the motors 38 are powered accordingly forthe hovercraft 10 to reach zero degrees XY axis. When this point isestablished, XYZ axis piezo gyros 56 lock on and stabilize the craft 10.If XY axis drift occurs, the NSEW transducers 64 reengage the process,thereby providing true homeostatic hover control feedback. The remotecontroller 12 provides digitized command signals which are received byreceiver 68. The signal interpreter chip 70 converts the signal to theappropriate directional and operational command.

While there have been shown in the drawings and described what arepresent to be preferred embodiments of the present invention, it isunderstood by one skilled in the art that changes in the structures,arrangement of structures, materials, electronic controls and programsand methods can be made without departing from the invention. Othervariations, applications and ramifications of the invention within theskill of a person in the art arc included in the present specificationand the following claims.

What is claimed is:
 1. A radio-controlled (RC) flying hovercraftcontrolled by a handheld RC controller separate and remote from the RCflying hovercraft, the RC flying hovercraft comprising: a set ofthrusters, each thruster including at least one blade driven by anelectrically powered motor, that provide aerodynamic lift for the RCflying hovercraft; a battery system positioned in the flying hovercraftand electrically coupled to the set of thrusters; a homeostatic controlsystem positioned in the RC flying hovercraft and operably connected tothe thrusters that automatically controls a thrust produced by eachthruster in order to automatically maintain a desired orientation of theRC flying hovercraft, the homeostatic control system including at leasta three dimensional, three-axis sensor system and associated controlcircuitry that dynamically determines a gravitational reference otherthan by dead reckoning for use by the homeostatic control system inautomatic control of said thrusters to maintain homeostaticstabilization in the desired orientation; and a radio frequency (RF)receiver positioned in the RC flying hovercraft and adapted to receivecommunications from the RC controller, the communications including thedesired orientation of the RC flying hovercraft used by the homeostaticcontrol system to automatically control the thrusters to maintain thedesired orientation, wherein the desired orientation communicated by theRC controller is determined based on a handheld structure housing asensor system in the RC controller that senses at least a twodimensional, two-axis sensed orientation of the handheld structure as aresult of a user remote from the RC flying hovercraft selectivelyorienting the handheld structure, whereby an actual moment-to-momentorientation of the RC flying hovercraft mimics a correspondingmoment-to-moment positioning of the RC controller based on the twodimensional, two-axis sensed orientation of the RC controller.
 2. The RCflying hovercraft of claim 1, wherein the flying hovercraft furthercomprises a foam body housing the thrusters within a perimeter of thebody.
 3. The RC flying hovercraft of claim 2, wherein the foam bodyincludes structure defining a set of ducts, each duct corresponding toone of the set of thrusters.
 4. The RC flying hovercraft of claim 3,wherein the set of ducts further comprise a screen cover disposed on anupper surface of the foam body corresponding to the set of ducts suchthat air flows through the screen cover into each duct and the at leastone blade of each thruster are protected by the screen cover.
 5. The RCflying hovercraft of claim 1, wherein the communications include thedesired orientation of the flying hovercraft and an intended motion inwhich the flying hovercraft is to be directed without any additionalcommunications being required for control of moment-to-moment balanceand stabilization of the RC flying hovercraft.
 6. The RC flyinghovercraft of claim 1, wherein the communications selectively includesoftware updates for the homeostatic control system from the web via anInternet connection.
 7. A method for operating a radio-controlled (RC)flying hovercraft using an RC controller separate and remote from the RCflying hovercraft, the method comprising: providing an RC flyinghovercraft having a set of generally downwardly directed thrusters, eachthruster including at least one blade driven by a battery powered motorto provide aerodynamic lift for the RC flying hovercraft under controlof a control system in the RC flying hovercraft that is responsive toradio frequency (RF) communications from the RC controller; causing anRF receiver in the control system in the RC flying hovercraft to receivecommunications from the RC controller, the communications including adesired orientation of the RC flying hovercraft, wherein the desiredorientation communicated by the RC controller is determined based on ahandheld structure housing a sensor system in the RC controller thatsenses at least a two dimensional, two-axis sensed orientation of thehandheld structure as a result of a user remote from the RC flyinghovercraft selectively orienting the handheld structure, causing asensor system in the control system of the RC flying hovercraft todynamically determine an actual orientation of the RC flying hovercraft,the sensor system including at least a three-dimensional, three-axissensor; and causing the control system in the RC flying hovercraft toautomatically and dynamically control a thrust produced by each of saidthrusters to achieve and selectively maintain the actual orientation ofthe RC flying hovercraft in response to the desired orientationcommunicated to the RC flying hovercraft by the RC controller and theactual orientation determined by the sensor system in the RC flyinghovercraft without any additional communications being required forcontrol of moment-to-moment balance and stabilization of the RC flyinghovercraft.